History:
Used to test a number of engines of all types, the first jet engine tested was
Metropolitan-Vickers F2 "Beryl" axial-flow engine in 1943, the first
flight being on 29/6/1943. The conversion was done by Armstrong Whitworth, with
the engine being mounted in the rear of the first prototype Lancaster (BT308)
in place of the rear turret, with a single intake being on the top of the fuselage
in front of the twin tail plane, the dorsal turret being removed, a year later
a Mk II (LL735) was fitted out in the same way, being used to test the F2/4
"Beryl" engine.

The second engine tested was the Armstrong
Whitworth AWX axial-flow engine, the conversion was done by Air Service
Training on a Lancaster Mk IV (ND784), The AWX engine was fitted under the
fuselage in the bomb bay, with the front and dorsal turret being removed,
testing starting from June 1945 and totaled 48 hours.

The last aircraft used for testing was VH742 and PD167,these
airframes were the most radically converted of all, with all turrets being removed
and the front and rear of the aircraft being streamlined. The two outer engines
were replaced by two Rolls Royce "Nean" engines. The conversion of
VH742 starting in October 1945, with it's first flight being on the 16/8/1946,
it continued to test the "Nene" engine until August 1949, when it
was refitted with the new "Tay" engine, but it was never to fly again
as the "Tay" was canceled in October 1949 and VH742 was dismantled.